The study of early infant behaviors and their relation to later cognitive and linguistic competence has been an enduring research focus in the investigation of human development. Research which aims to predict cognitive and linguistic abilities in later childhood based on early infant behavior, implicate infant perceptual-cognitive abilities as likely analogs for childhood information-processing skills. The primary aim of this study is to examine the specific relationship between early perceptual-cognitive abilities (as indexed by habituation, recognition memory, and auditory temporal processing) and later cognitive and linguistic development Speed of encoding appears to be the critical factor in differential performance on perceptual-cognitive tasks. Measures of perceptual- cognitive abilities in infancy, such as habituation decrement and recognition memory, are in turn related to performance on childhood linguistic and cognitive tasks. Similarly, studies with language impaired children implicate a specific deficit in rate of sensory and perceptual information processing. Previous research has found auditory temporal processing and memory deficits to be highly predictive of developmental speech and language impairment We propose to bring together two promising lines of research which, to our knowledge, have not previously been integrated, in order to directly examine the role of speed of encoding in infant perceptual-cognitive abilities and its subsequent impact on later cognitive and language outcomes. We will pursue these goals in two ways. First, by continuing to develop and refine our infant operant conditioning paradigm that facilitates assessment of auditory temporal processing (ATP) in the first year of life and collecting cross-sectional, normative data on ATP for infants 4- to 9- months-of-age. Second, by examining prospectively the developmental course of early perceptual memory, information processing, and temporal processing in three infant populations expected to differ in the course of language development and the incidence of specific language impairment: normal term infants, preterm very low-birth-weight (VLBW) infants, and infants from families with a positive history of specific language impairment (LI). The primary rationale for the proposed research is to address and integrate existing theories of early perceptual, cognitive and language development. Ultimately, these studies may lead to the development of specific measures which may provide for earlier prediction of subsequent cognitive and/or language disorders.